A team in Edinburgh have identified a gene that controls the size of the human brain.

The team, led by Andrew Jackson of the Medical Research Council (MRC) studied families who have members with Seckel syndrome, a condition which retards growth in the womb, leading to short stature and markedly reduced brain size, known as microcephaly.

The team found that small brain size is linked to faults in a gene called Pericentrin, or PCNT for short.
The PCNT gene forms part of the centrosome, an organ found in human cells that was first discovered in 1888 by Thomas Boverie, who described it as the "special organ of cell division".
Since growth of our bodies depends on cells dividing, it stands to reason that defects on the process of cell division will have an impact on the size of both our bodies and our brains. Indeed, this theory is further substantiated by the fact that other studies of microcephaly have found defects in other genes involved in the working of the centrosome.

If microcephaly is hereditary, as it appears to be in most cases, then the results of this study may be the first step in developing a screening test for its potential and may even lead to the possibility of a cure.

A copy of the full report was published in the journal Nature Genetics (December 2007). A copy of the article can be obtained for a modest fee by visiting their web site at www.nature.com/ng/index.html